Edmond hippolyte derepas and alexandre ernest derepas



N. 770,421. PATENTED SEPT; 20, 1904. ELI-I. & A. E. DEREPAS. PHOTOGRAPHIC PAPER.

APPLICATION FILED SEPT. 24, 1901.

No MODEL.

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UNITED STATES Patented September 20, 1904.

PATENT OFFICE.

PHOTOGRAPHIC PAPER.

SPECIFICATION forming part of Letters Patent No. 770,421,

dated September 20, 1904.

Application filed September 24, 1901. Serial No. 76,349. (No model.)

To all whom, it may concern:

Be it known that we, EDMOND HIPPOLYTE DEREPAS and ALEXANDRE ERNEST DEnErAs, manufacturers of photographic albums and supplies, both of 99 Rue Saint Honor, in the city of Faris, Republic of France, have invented an Improved Photographic Paper, of which the following is a full, clear, and exact description.

Our invention relates to a new photographic paper made in such a manner as to enable the operator to mount his positive prints or proofs dry-that is to say, without their being subject to any distortion and without it being necessary to apply any adhesive material to the paper. In practice our new paper thus partly suppresses the preparatory operations which are required in mounting positive prints on bristol-board or other mounts or supports for receiving them.

The invention is illustrated in the accompanying drawings, in which- Figure 1 is a perspective view of a paper or card with the sensitive coating and adhesive coating turned away at one side, and Fig. 2 is a sectional view.

In the drawings, A indicates the paper or card, B the sensitive coating, and C the adhesive coating.

Our improved paper is formed by the paper proper bearing on the right side the coating which is sensitized or to be sensitized, and on the reverse side a coating of a material which is adhesive when hot-such as a gum-resin, for example. It is obvious that th'e gum-resin or other adhesive material employed shall not be capable of being attacked by water or by the various baths used to develop or to tone and tix the print. In practice we give the preference to gum-lac, and the latter employed in aqueous or alcoholic solution is applied on the reverse side of the suitably-sized photographic paper-that is to say, on the side opposite to the sensitive side or face, (rightside.) Although there would be no inconvenience in taking the opposite course, we prefer from the point of view of he attention which is required in the manu- E .i :tu re to prepare first the reverse side before of gum-lac or other applying the emulsion to and sensitizing the 5o right side. The photographic paper thus made can be subjected to all the ordinary manipulations or operations in exposing, developing, toning, fixing, and washing, which represent, in a word, all the operations necessary for the different kinds of sensitive surfaces. These operations being completed and the paper absolutely dry,` in order to mount the positive print it is only necessary to place it on a bristol-board, a card, or any other 6o mount or support for receiving it and to sub* ject the whole to the action of heat and pres sure, the gum-lac only melting at a comparatively high temperature. It is thus possible to employ a sufIiciently-high temperature and pressure to give the desired glazing to the print without having to fear creasing or the like.

It is easy to understand that since the mount ing of the print is effected dry the said print 7o retains its proportions with absolute faithfulf ness to the negative from which the sensitive surface received the image when it was placed in contact therewith also in a dry condition, Moreover, if the passage of the print through 7 5 the baths necessary for its completion has vbeen able to throw the lines thereof out of their correct proportions by the extension of the paper in the moist condition the coating adhesive material mper 8o meable to and not capable of being attacked by liquids, which covers its rear or reverse side or face, obliges the paper when dry to again take the exact dimensions which it had at the time when it was exposed in the print- 8 5 ing-frame. We will also remark that our paper thus prepared for dry mounting has the property of isolating the print from the mount or support by an impermeable layer, which checks any chemical action capable of 9o ultimately deteriorating the image. Finally, our.paper obviates nearly all the delicate and tedious operations of the present method of mounting on cards or bristol-board by per Initting the photographer to effect a considerable economy in time and labor. As above mentioned, our paper can, moreover, be of any kind from the photographic point of view-that is to say, it can be albuminous, is not sensitive to the aotion of liquid baths,

treated with baryta or coated with emulsion, substantially as described.

and be sensitized or not. It can, moreover, The foregoing specification of our imeither be a printing-out paper or one which proved photographie paper signed by us this I5 5 requires developing'to bring out the image. y12th day of September, 1901.

These various conditions 1n no Way change EDMOND HIPPOLYTE DEREPAS- the nature of our said invention.

Te Claim; ALEXANDRE ERNEST DEREPAS. A photographic paper provided on its re- Witnesses: IO verse side Witini a coating of solid gum-lao EDWARD P. MACLEAN,

which is adhesive when pressed hot and which MAURoE H. PIGNET. 

